BPF: Draw and label a flowchart from a process description

Flowchart Development

We know what a flowchart is and what purpose it serves (organizing our thinking about a process) from the early part of this course. Let's look at a few flowchart requirements and then some conventions:


There are three methods for conveying stream flows/compositions:


Additional Flowchart Considerations


Flowcharts may be scaled.

It is not surprising that changing a flowchart from using units of lbm to kg should not make a difference to the validity of the flowchart. (unit conversions will not change whether the flowchart is balanced or not!)

With a little thinking then, it should be clear that changing the basis of calculation of a flowchart should not make a difference!


A basis of calculation is the one stream whose amount (mass or motes) or flow rate (mass flow or molar flow) is chosen as the "least common denominator" for the problem (the units that you match everything to, as well as the scale you match everything to!).


For example: both of these expressions are true

60s + 120s = 180s
1 min + 2 min = 3 min

Changing the units did not effect the truth of the statement. It should be equally clear that scaling up (multiplying by a number greater than 1) or scaling down (multiplying by a number less than 1) also makes little difference.

60s + 120s = 180s
6s + 12s = 18s (multiply by 1/10)
120s + 240s = 360s (multiply by 2)


Draw and label a flowchart from a process description.


Let's try and work through an example.